A finite automaton, also known as a finite-state machine or finite-state automaton, is a mathematical model of computation that is used to recognize patterns within input taken from some character set or alphabet. It is an abstract machine that can be in exactly one of a finite number of states at any given time. A finite automaton consists of a finite set of states, a set of input symbols, an initial state, a set of final states, and a transition function. The transition function specifies the next state of the automaton given the current state and the input symbol. There are two types of finite automata:

• Deterministic Finite Automata (DFA): In a DFA, the machine goes to one state only for a particular input character. It does not accept the null move.

• Non-Deterministic Finite Automata (NFA): In an NFA, the machine can transmit any number of states for a particular input. It can accept the null move.

Finite automata are used to characterize regular languages and to analyze and recognize natural language expressions. They are also used in modeling reactive systems and are significant in many different areas, including electrical engineering, linguistics, computer science, philosophy, biology, mathematics, video game programming, and logic.